Plug and socket connection



0d. 7, 1969 H,GREUL1CH ETAL 3,471,824

PLUG AND SOCKET CONNECTION Filed April 16, 1965 Int. ci. non i3/54, 13/22 Us. ci. 339-61 The present invention relates to a plug and socket connection for electrical conductors. More specifically, the present invention relates to a plug and socket connection for electrical conductors which include a pair of elongated members preferably formed from elastically yieldable plastic material which can be interengaged with each other and through which a pair of electrical conductor means respectively extend arranged in such a manner that when the members are interengaged with each other, cooperating end portions of the electrical conductor means will establish an electrical connection between the conductor means.

It is an object of the present invention to provide plug and socket connection for electrical conductors of the aforementioned type in which the two members can be interengaged with each other in a substantially watertight manner and such that the two members may be secured to each other against separation in axial direction and also resistant against forces which impart a bending moment to the connection.

`It is a further object of the present invention to provide a plug and socket connection of the aforementioned type in which the two members can be easily engaged `and properly secured to each other.

It is an additional object of the present invention to provide a plug and socket connection of the aforementioned type which is constructed of few and relatively simple parts so that the connection may be manufactured at reasonable cost and will stand up trouble free under extended use.

With these objects in view, the plug and socket connection for electrical conductors according to the present invention mainly comprises a first elongated member formed at one end thereof with `a cavity so as to provide at said one end an annular wall which is formed with a plurality of angularly displaced slots extending from the free edge of the annular wall partly through the length of the wall, and in which the thickness of the annular wall increases toward the free edge thereof. At least the annular wall of the rst member is formed yfrom elastically compressible material. The plug and socket connection comprises further a second elongated member which has at one end thereof a head having an end portion tightly tting into the cavity of the rst member and at a given distance from the free end of the aforementioned end portion an undercut portion of a cross section smaller than that of the end portion. A sleeve of substantially rigid material surrounds the first member and the sleeve is movable in longitudinal direction with respect to the first member between a retracted releasing position in which at least the portion of increased thickness of the annular wall of the first member projects beyond one end of the sleeve, and an advanced locking position in which the aforementioned end of the sleeve substantially coincides with -the one end of the rst member so that, after the head of the second member is pushed into the cavity of the first member, movement of the sleeve from the retracted releasing position to the 9 Claims advanced locking position will press the portion of in- F creased thickness of the annular wall into the undercut portion of the head to thus secure the members against nited States Patent O ice displacement in longitudinal direction with respect to each other. The connection includes further a pair of electrical conductor means respectively extending through the first and the second member insulated therefrom. The conductor means have respectively cooperating end portions establishing an electrical connection between the conductor means when the members are secured to each other in the afoementioned manner.

The novel features which are considered as characteristic for the invention are set forth in particular in the appended claims. The invention itself, however, both as to its construction and its method of operation, together with additional objects and advantages thereof, will be best understood from the following description of specic embodiments when read in connection with the accompanying drawings, in which:

FIG. l is a partially sectioned, partial view of the plug and socket connection according to the present invention and FIG. l shows the two members in disengaged position;

FIG. 2 is a partial, partially sectioned view similar to FIG. l drawn to a slightly enlarged scale and showing the head on one member located in the cavity of the other member and the sleeve in retracted position;

FIG. 3 is a partial, partially sectioned view similar to FIG. 2, likewise drawn to an enlarged scale, and showing the sleeve in advanced locking position; and

FIG. 4 is a partial, partially sectioned view similar to FIG. l and showing a modification.

Referring now to the drawings, and more specifically to FIG. l of the same, it will be seen that the plug and socket connection of the present invention preferably comprises a socket Ipart 10 and a plug part 11. The part 10 includes a first elongated cylindrical member 12 preferably formed from elastically yieldable material, such as plastic, which is formed at one end thereof, shown in PIG. 1 at the lower end, with a coaxial substantially cylindrical cavity 13 so as to -form at this lower end of the member 12 an annular wall 14 defining -the cavity. The annular wall 14 is formed with a plurality of angularly displaced slots `16 extending from the free lower edge of the annular wall in `substantially axial direction partly therethrough and ending at a distance b from the transverse end face 25 of the cavity which extends substantially normal to the axis of the first member 12. The slots 16 divide thus the end portion of the annular wall 14 in a plurality of iingers 17. The wall thickness of the end portion of the annular wall 14 gradually increases in radial outward direction so as to provide at said end portion an outer cone surface '15 including lan angle B (FIG. 2) -with the axis of the cylindrical member 12. The member 12 is preferably provided at the outer surface thereof and at a portion spaced from the end in which the cavity \13 is formed with an outer Vscrew thread 1S with which an inner screw thread of a sleeve 19, which is preferably formed lfrom metal, is threadingly engaged.

The second part 11 preferably includes also `an elongated cylindrical member 20 of insulating material, preferably plastic, which has a diameter substantially equal to the outer diameter of the sleeve 19. The second member 20 has at an end thereof a head 21 having a substantially cylindrical end portion 22 of an outer diameter substantially identical to the inner diameter of the cavity 13 in the first member 12 and of La height a not exceeding7 and preferably slightly smaller than the distance b, that is distance of the inner ends of the slots 16 from the end face 25 of the cavity in the rst member. The head 21 includes further an undercut portion shown as a substantially fnustoconical portion 23 having an outer abutment surface including an angle A with .the axis of the Ihead 21, which angle is smaller than the aforementioned angle B which.

the outer frustoconical surface of the end portion of the annular wall includes with the axis `of the iirst member 12. The fnustoconical portion 23 of the head is joined at its small diameter and by a substantially cylindrical portion 24 with the remainder of the second member 20 so as to form on the latter an annular shoulder face 29.

An electrical conductor means 32 extends in axial direction through the insulating member 12 embedded therein, and the conductor means 32 may have a male connecting portion 33 extending through the cavity 13 and beyond the end of the member 12 in which the cavity is formed. A conductor means 34 extends axially through the second member 11 embedded therein and the conductor means 34 may include a female end portion 35 connected thereto and ending liush with the end face 26 lof the head to be engaged by the male end portion 33 when the head 21 is pushed into cavity 13 of the first member. The specific construction of the male and female connecting portions of the conductor means 32 and 34 do not tform part of the present invention and any well known connecting portions which are adapted to interengage into each other may be used. The conductor means 32 and 34 may each consist yof a single conductor respectively coaxially arranged with members 12 and 20 or of two `or more conductors extending in axial direction respectively through the aforementioned members. Obviously, the conductor means 34 may have a male end portion projecting beyond the end face 26 of the head and the conductor means 32 may have a female end prortion ending iiush with the bottom face 25 of the `cavity 13.

The lplug and socket connection as :above described will operate as follows:

The head 21 on the member 11 is pushed into the cavity 13 in the member 12 until the end face 26 on the cylindrical portion 22 ofthe head engages the traverse end face 25 of the cavity, as shown in FIG. 2. In this position, the edge 27 of the cylindrical portion 22 of the head 21 will Ibe located at a portion of the cavity between the end face 25 thereof and the inner ends of the slots 16, that is at a portion of the annular wall 14 which is not divided by the slots 16. The sleeve 19 is then threaded relative to the member 12 in such 1a ydirection that the sleeve is moved from the retracted releasing position, as shown in FIG. 2, to the advanced locking position, as shown in FIG. 3, so that the lead-in surface 28 of `the sleeve 19 will engage the outer fnustoconical surface 15 off the end portion of the wall 14 to press the portion of increased wall thickness iagainst the abutment surface of the frustoconical portion 23 of the head 21. Since the diameter of the cylindrical portion 22 of the head is substantially identical with the inner diameter of the cavity 13, and since the angle B which .the outer frustoconical surface of the end portion of the wall 14 includes with Ithe axis of member 12 is greater than the angle the abutment surface `of the conical portion 23 of the head includes with the `axis of the head, pressing of the inner surfaces of the fingers 17 against the abutment surface of the conical portion of the head will result in an axial force pressing the end face 26 of the head 21 against the traverse end face 25 of the cavity 13, thereby providing a sealing engagement between the two surfaces. The height of the conical portion 23 has to be chosen in such a manner that when the fingers 17 are pressed against the conical surface of the conical portion 23, the portions of maximum thickness of the lingers will engage the conical abutment surface tof the fmstoconical portion 23 of the head, as shown in FIG. 3, and the inner surface of the iingers fare preferably slightly rounded at the lower ends thereof, as shown in FIGS. l-3. It should be further noted that the lingers 17 are pressed against the outer surface of the tfrustoconical portion 23 of the head before the lower end of the sleeve 19 engages 'the shoulder face 29 on the member 11 yand preferably the cooperating threads on the sleeve 19 and `on the member 12 are made in such a manner that the sleeve is stopped shortly before the lower ends thereof engage the shoulder face 29 or in such a manner that the sleeve cannot be advanced -beyond the position in which the lower end thereof just toruches the shoulder face 29. Since the unslotted portion of the wall 14 extends beyond the edge 27 of the cylindrical portion 22 of the head 21 an 'additional se-al is also provided lat the edge 27 by the wall 14.

To improve the seal at the bottom of the cavity 13, a shallow cavity 31, preferably in the form of a spherical segment extending from the end face 26 of the cylindrical portion 22 of the head into the latter, may be provided which has at the end face 26 a maximum diameter smaller than the outer 'diameter of 'the cylindrical portion so that the head 21 will engage the end face 25 .of the cavity along an annular face portion, increasing thereby the specific surface pressure between the annular end face of the head and the end 'face 25 of the cavity.

The embodiment shown in FIG. 4 is substantially identical with the embodiment shown in FIG. 1 and dilfers therefrom in that an annular sealing ring 30 of compressible material is provided on lthe cylindrical portion 21 of the head. Furthermore, in this construction the cooperating threads on the sleeve 19 and on the member 12 are made in such a manner that the sleeve 19 can be threaded in tight engagement with the shoulder face 29 on the second member 20 tending thereby to move the member 11 away from the member 12. Since during movement of the sleeve 19 from the retracted to the advanced position the portions of the fingers 17 of increased wall thickness are pressed inwardly, the inwardly pressed finger portions will be pressed during movement of the two members slightly away tfrom each other with increasing pressure against the conical abutment face of the frustoconical portion 23 of the |head so that the two members will be securely connected to each other and provide at the sealing ring 13 a perfect seal. The abutment yof the end of the sleeve 19 on the shoulder face 29 will also Imake the connection resistant to bending forces applied thereto.

The plug and socket connection according to the present invention can be constructed with small dimensions, for instance with a diameter not exceeding 5 mm.

It will be understood that each of the elements described above, or two or more together, may also find a `useful application in other types of plug and socket connection differing from the types described above.

While the invention has been illustrated and described as embodied in plug and socket connections, it is not intended to be limited to the details shown, since various modifications and structural dhanges may be made without departing in any way from the spirit of the present invention.

Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can by applying current knowledge readily adapt it for various applications without omitting features that, from the standpoint of prior art, fairly constitute essential characteristics iof the generic or specific aspects of this invention.

What is claimed as new and desired to be secured by Letters Patent is:

1. A plug and socket connection for electrical conductors comprising, in combination, a lirst one piece elongated member of nonconductive material having at one end thereof an annular wall forming a cavity, said annular wall being formed with a plurality of angularly displaced slots extending from the free edge of said annular wall partly through the length of said wall so as to form tongues and the wall thickness of said annular wall increasing by increase of the ouside diameter thereof, toward the free edge thereof; a second one-piece elongated member of nonconductive material having at one end thereof a head having an end portion fitting into said cavity of said first member, and at a given distance from the free end of said end portion, an undercut portion of a cross section 'smaller than that of said end portion; a sleeve having a length considerably longer than the length of said annular wall, said sleeve surrounding said iirst member and being movable in longitudinal direction with respect thereto between a retracted releasing position in which at least said tongues of increased thickness project beyond one end of said sleeve and an advanced locking position in which said one end of said sleeve coincides With said one end of said first member so that, after said head of said second member is pushed into said cavity of said first member, movement of said sleeve from said retracted releasing position to said advanced locking position will press the tongues of increased thickness into said undercut portion of said head to thus secure said members against displacement in longitudinal direction with respect to each other; and a pair of electrical conductor means respectively extending through said first and said second members, said conductor means having respectively cooperating end portions establishing an electrical connection between said conductor means when said members are secured to each other.

2. A plug and socket connection as set forth in claim 1, wherein said first member is formed from plastic material and said second member is formed of elastically yieldable plastic material.

3. A plug and socket connection as set forth in claim 1, wherein said first member is formed at a portion thereof axially spaced from said annular wall with an outer screw thread, and wherein said sleeve is formed at a portion spaced from said one end thereof with an inner screw thread threadingly engaging said outer screw thread of said first member.

4. A plug and socket connection as set forth in claim 1, wiherein said sleeve has at said one end thereof an inner lead-in surface portion gradually increasing in direction toward said one end.

5. A plug and socket connection as set forth in claim 1, wherein said cavity formed by said annular wall of said first member has an inner substantially cylindrical surface and said end portion of said second member has an outer substantially cylindrical surface of a diameter substantially equal to that of said inner cylindrical surface of said cavity.

6, A plug and socket connection as set forth in claim 5, and including a ring of compressible material arranged about said cylindrical surface of said end portion of said head.

7. A plug and socket connection for electrical conductors comprising, in combination, a first elongated, substantially cylindrical member of elastically yieldable nonconductive material, said first member being formed at one end thereof with a coaxial substantially cylindrical cavity so as to provide at said one end an annular wall, said annular wall being formed with a plurality of angularly displaced slots extending in substantially axial direction from said one end of said first member partly through said wall and ending at a predetermined distance from the inner end of said cavity, the wall Itlhickness of said annular wall gradually increasing in radially outward direction direction from said predetermined distance toward said one of end of said rst member so as to define an outer substantially frustoconical surface having a given cone angle; a second elongated member of nonconductive material having at one end thereof a head having a substantially cylindrical end portion of a height slightly smaller than said predetermined distance and fitting into said cavity of said first member and next to said cylindrical end portion a substantially fnustoconical portion having an outer abutment surface of a cone angle smaller than said given angle and tapering in a direction away from said cylindrical portion; a sleeve of substantially rigid material surrounding said first member and being movable in longitudinal direction with respect thereto between a retracted releasing position in which at least the portion of increased thickness of said annular Wall projects beyond one end of said sleeve and an advanced locking position in which said one end of said sleeve coincides with said one end of said first member so that, after said head of said second member is pushed into said cavity of said first member, movement of said sleeve from said retracted releasing position to said advanced locking position will press the portion of increased thickness against said abutment surface of said frustoconical portion of said head resulting in an axial force pressing the free end face of said cylindrical portion of said head on said second member against the inner end face of said cavity in said first member to thus secure said members against displacement in longitudinal direction with respect to each other; and a pair of electrical conductor means respectively extending through said first and said second member insulated therefrom, said conductor means having respectively cooperating end portions establishing an electrical connection between said conductor means when said members are secured to each other.

8. A plug and socket connection as set forth in claim 7, wherein said cavity has at its inner end a plane end face substantially normal to the axis of said first member, and wherein said cylindrical portion of said head of said second member is formed with a coaxial cavity extending from the end face of said head into the latter and having at said end face a smaller diameter than the outer diameter of said cylindrical portion so that said end face of said cylindrical portion is pressed along an outer annular portion against said plane face of said cavity.

9. A plug and socket connection for electrical conductors comprising, in combination, a first elongated substantially cylindrical member of elastically yieldable plastic material, said first member being formed at one end thereof with a coaxial substantially cylindrical cavity so as to provide at said one end an annular wall, said annular wall having an end portion of a Wall thickness gradually increasing in outward direction toward said one end of said first member, said end portion of said wall being formed with a plurality of axially extending slots therethrough uniformly spaced from each other, said first member being formed at a portion thereof axially spaced from said annular wall with an outer screw thread; a second elongated member of elastically yieldable plastic material having at one end thereof a head having a substantially cylindrical end portion fitting into said cavity of said first member and at a given distance from the free end of said cylindrical end portion an undercut portion of a diameter smaller than that of said cylindrical end portion, said second member having a portion of increased diameter carrying said head so as to form an annular shoulder face substantially normal to the axis of said head; a ring of compressible material arranged about the cylindrical surface of said cylindrical portion of said head; a sleeve of substantially rigid material surrounding said first member and lbeing formed at a portion thereof spaced from one end of said sleeve with an inner screw thread threadingly engaging said outer screw of said first member so as to be axially movable with respect to the first member between a retracted releasing position in which at least the portion of increased thickness of said annular wall projects beyond said one end of said sleeve, and an advanced locking position in which said one end of said sleeve extends at least up to said one end of said first member so that, after said head of said second member is pushed into the cavity of said first member, movement of said sleeve Ifrom said retracted releasing position to said advanced locking position will press the portion of increased thickness of said annular Wall into said undercut portion of said head to thus secure said members against displacement in longitudinal direction with respect to each other, said screw threads on said first member and said sleeve being arranged so that said one end of said sleeve may abut in said adlvanced position of said sleeve against said shoulder face; and a pair of electrical conductor means respectively ex- 7 tending through said first and said second member, said conductor means having respectively cooperating end portions establishing an electrical connection between said conductor means when said members are secured to each other.

References Cited UNITED STATES PATENTS 6/1942 Cannon et al 339-89 X FOREIGN PATENTS 1,138,994 2/1957 France.

RICHARD E. MOORE, Primary Examiner JOSEPH H. MCGLYNN, Assistant Examiner U.S. Cl. X.R. 339-91 

1. A PLUG AND SOCKET CONNECTION FOR ELECTRICAL CONDUCTORS COMPRISING, IN COMBINATION, A FIRST ONE PIECE ELONGATED MEMBER OF NONCONDUCTIVE MATERIAL HAVING AT ONE END THEREOF AN ANNULAR WALL FORMING A CAVITY, SAID ANNULAR WALL BEING FORMED WITH A PLURALITY OF ANGULARLY DISPLACED SLOTS EXTENDING FROM THE FREE EDGE OF SAID ANNULAR WALL PARTLY THROUGH THE LENGTH OF SAID WALL SO AS TO FORM TONGUES AND THE WALL THICKNESS OF SAID ANNULAR WALL INCREASING BY INCREASE OF THE OUTSIDE DIAMETER THEREOF, TOWARD THE FREE EDGE THEREOF; A SECOND ONE-PIECE ELONGATED MEMBER OF NONCONDUCTIVE MATERIAL HAVING AT ONE END THEREOF A HEAD HAVING AN END PORTION FITTING INTO SAID CAVITY OF SAID FIRST MEMBER, AND AT A GIVEN DISTANCE FROM THE FREE END OF SAID END PORTION, AN UNDERCUT PORTION OF A CROSS SECTION SMALLER THAN THAT OF SAID END PORTION; A SLEEVE HAVING A LENGTH CONSIDERABLY LONGER THAN THE LENGTH OF SAID ANNULAR WALL, SAID SLEEVE SURROUNDING SAID FIRST MEMBER AND BEING MOVABLE IN LONGITUDINAL DIRECTION WITH RESPECT THERETO BETWEEN A RETRACTED RELEASING POSITION IN WHICH AT LEAST SAID TONGUES OF INCREASED THICKNESS PROJECT BEYOND ONE END OF SAID SLEEVE AND AN ADVANCED LOCKING POSITION IN WHICH SAID ONE END OF SAID SLEEVE COINCIDES WITH SAID ONE END OF SAID FIRST MEMBER SO THAT, AFTER SAID HEAD OF SAID SECOND MEMBER IS PUSHED INTO SAID CAVITY OF SAID FIRST MEMBER, MOVEMENT OF SAID SLEEVE FROM SAID RETRACTED RELEASING POSITION TO SAID ADVANCED LOCKING POSITION WILL PRESS THE TONGUES OF INCREASED THICKNESS INTO SAID UNDERCUT PORTION OF SAID HEAD TO THUS SECURE SAID MEMBERS AGAINST DISPLACEMENT IN LONGITUDINAL DIRECTION WITH RESPECT TO EACH OTHER; AND A PAIR OF ELECTRICAL CONDUCTOR MEANS RESPECTIVELY EXTENDING THROUGH SAID FIRST AND SAID SECOND MEMBERS, SAID CONDUCTOR MEANS HAVING RESPECTIVELY COOPERATING END PORTIONS ESTABLISHING AN ELECTRICAL CONNECTION BETWEEN SAID CONDUCTOR MEANS WHEN SAID MEMBERS ARE SECURED TO EACH OTHER. 